1. Field of the Invention
This invention relates to money-operated games and, in particular, to games utilizing a claw with an operator-positionable crane to attempt to pick up prizes, including the way in which the claw's strength is controlled.
2. Problems in the Art
A coin operated crane game consists of an electronic control system and a mechanical system that allows a player to purchase a chance to win a prize by skillful manipulation of player controls. The controls consist of a joystick and/or buttons, which are activated by the insertion of coins or cash into the game. These controls allow the player to move a crane head in front/back and left/right positions and then drop a claw which will pick up prize merchandise if skillfully and properly manipulated. When the claw drops to the bottom of its travel, the control electronics closes the claw, raises the claw, positions its over a prize delivery shoot and releases the prize if it is held by the claw. Motors are used to move the crane head and to move the claw up and down. The claw is activated by a solenoid. This invention concerns the control of that solenoid. The equipment operator presets the nominal strength of that solenoid so that the skill level required to win is consistent with the business economics of operating the equipment.
It is of course preferable to have a game of this type be economically profitable. If the claw strength were unlimited, or at least maximized, the winning of prizes could approach being automatic. This would skew the factors of skill and chance towards the player, which could severely restrict or even defeat profitability of the game.
Therefore, to make the game have a reasonable level of skill and chance, and to allow game owner profitability, claw-gripping strength can be adjustable.
A first prior art example of a way to operate and adjust gripping strength of the claw uses a relay and a power potentiometer, as shown in FIG. 6, to control the solenoid, which in turn determines gripping strength of the claw. A microcomputer controls the relay. This design has relay and potentiometer failures at a higher than desired rate. Also, this design is susceptible to undesirable variations of claw strength due to variations of line voltage and power supply load changes (from motor operation, etc.).
A second example of prior art uses a timer circuit to pulse width modulate the solenoid drive to control claw-gripping strength, as shown in FIG. 7. The timer circuit is itself controlled by a potentiometer. A microcomputer enables the timer circuit at the appropriate time. This system has significant voltage noise due to the rapid switching of the solenoid to control its current and a lack of precision due to the nature of the timer control circuit. Also, this design, like the first example of FIG. 6, is susceptible to undesirable variations of claw strength due to variations of line voltage and power supply load changes (from motor operation, etc.).
It can therefore be seen that the state of the art utilizes voltage control for energizing the solenoid. These methods have been found to have weaknesses. Therefore, there is a real need for improvement in the art.
It is therefore a principal object of the present invention to provide an apparatus and method for crane game claw control that improves over or solves the problems and deficiencies in the art.
Another object of the present invention is to provide an apparatus and method as above described which overcomes the problems associated with variations of line voltage, power supply load changes, and voltage noise.
Other objects, features, and advantages of the present invention include:
a. Increased reliability of operation and electrical components; PA0 b. Improved level of control of claw gripping strength; PA0 c. Improved control of game pay out; PA0 d. Improved flexibility of control and operation; PA0 e. Improved economics, efficiency, and durability.
These and other objects, features and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.